An overhead view of a tent city built for U.S. military personnel at Al Udeid Air Base in Qatar. This area of the base was named Camp Andy in memory of Master Sgt. Evander Earl "Andy" Andrews, a civil engineer who died on October 10, 2001, in a construction accident.

Units: 379th Air Expeditionary Wing; 44th, 340th and 379th Expeditionary Air Refueling squadrons; 434th and 911th Air Refueling Wings; and 93rd Air Control Wing, according to military research group Globalsecurity.org.

Role: The $1.4 billion base has the longest runway (2.8 miles) in the region and can accommodate up to 120 aircraft. Early in the Afghanistan campaign, F-16 fighters and E-8C Joint Stars reconnaissance planes that monitor ground units were based here, along with refueling tankers.

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